PT  - JOURNAL ARTICLE
AU  - K. Landheer
AU  - A. Sahgal
AU  - S. Das
AU  - S.J. Graham
TI  - Constrained Source Space MR Spectroscopy: Multiple Voxels, No Gradient Readout
AID  - 10.3174/ajnr.A4319
DP  - 2015 Aug 01
TA  - American Journal of Neuroradiology
PG  - 1436--1443
VI  - 36
IP  - 8
4099  - http://www.ajnr.org/content/36/8/1436.short
4100  - http://www.ajnr.org/content/36/8/1436.full
SO  - Am. J. Neuroradiol.2015 Aug 01; 36
AB  - BACKGROUND AND PURPOSE: Our goal was to develop a novel technique for measuring a small number of localized spectra simultaneously and in a time-efficient manner.MATERIALS AND METHODS: Using appropriate radiofrequency pulses, the magnetization from multiple voxels is excited simultaneously and then separated (reconstructed) by using the individual coil-sensitivity profiles from a multichannel receiver coil. Because no gradients are used for k-space encoding, constrained source space MR spectroscopy provides a time advantage over conventional spectroscopic imaging and an improved signal-to-noise ratio per square root of unit time over single-voxel spectroscopy applied at each successive location. In the present work, we considered prototype application of constrained source space MR spectroscopy for 2 voxels.RESULTS: Experimental data from healthy volunteers and simulation results showed that constrained source space MR spectroscopy is effective at extracting 2 independent spectra even in the challenging scenario of the voxels being closely spaced. Also, from 6 patients with various types of brain cancer we obtained 2-voxel constrained source space MR spectroscopy data, which showed spectra of clinical quality in half the time required to perform successive single-voxel MR spectroscopy.CONCLUSIONS: Constrained source space MR spectroscopy provides clinical quality spectra and could be used to probe multiple voxels simultaneously in combination with Hadamard encoding for further scan-time reductions.CSSMRSconstrained source space MR spectroscopyPRESSpoint-resolved spectroscopy sequenceSVSsingle-voxel spectroscopy